L. Martarello et al., PREPARATION OF THIAZOLOCARBAZOLES VIA THE FISCHER INDOLE SYNTHESIS, Journal of the Chemical Society. Perkin transactions. I, (22), 1995, pp. 2941-2944
Treatment under Fischer acidic conditions, of tetrahydrobenzo[d]thiazo
lones and/or arylhydrazonobenzo[d]thiazole derivatives has given a var
iety of thiazolocarbazoles.